Battery/alternator

[andywhy]

Remember that all those fuses could be in use at once so that's more than a 40A load. The bigger the alternator, the less strain there is on the alternator windings at high loads, so it'll last longer. It'll also mean you're less likely to overload it (and in turn overheat it) with turning everything on and end up draining the battery. The stock is about 80A I believe but I always found mine struggled a bit with fan, glow plugs (when starting from cold), lights and demist on (needed in winter). It often drained from the battery for a while which isn't good for it. Your choice, go with stock size if you're not sure.